Calender



pril 5, 1966 w. o. BiscHoFF CALENDER INVENTOR.

Filed Sept. 1, 1964 Irl 'm WALDEMAR O. BISCHOFF ATTORNEY.

United States Patent O 3,244,090 CALENDER Waldemar O. Bischoff, Holyoke,Mass., assigner to B. F. Perkins & Son, Inc., Holyoke, Mass. Filed Sept.1, 1964, Ser. No. 393,537 2 Claims. (Cl. 10G-162) This invention relatesto structural refinements in roller equipment of the type used in themanufacture of sheet material such as paper or textiles and has specialreference to calender apparatus of improved construction.

Conceivably, the principles of the invention have other applications, asfor instance in the case of compression rolls used in the clothfinishing process known as fulling and washing in the textile art. Insuch process, just as in paper calendering and/or in many otherapplication-s where this invention will have utility, it is normallynecessary or desirable to subject the work material to pressure-s ofhigh magnitude in order to perform various operations thereupon, such asthe removal of moisture, reduction of thickness, treatment of thesurface, andthe like, by passing the work material between largecylindrical rolls disposed invsets or stacks called calendering units.In one form of such unit, it is known to mount one roll of an opposedpair, or more than one roll of a series, in yielding relation to anopposing roll or rolls, and for a multiplicity of valid reasonsincluding to prevent the exertion of excessive pressure as varyingthicknesses of the work material being compressed are passedtherebetween. Resort has commonly been had to the use of spring loadingor similar devices to load the yieldably mounted roll.

-The invention hereof advantageously exploits this yielding relationshipof opposed rolls to teach a method of replacing a roll without astoppage of the machine employing same.

According to the known prior art, transversely-spaced calender sideframes have vertically-disposed slots for the reception of bearings, inwhich bearings, the opposite ends of the rolls are journalled. Foraiding roll removal, sides of the side frames are cut away to provideopenings into the slots, and cheeks are fitted in such openings and areremovably secured therein. To remove a roll, the cheeks are removed fromthe openings, wherefor the roll ends and bearings may be withdrawnoutwardly. Reversely, installing a roll, the roll ends and bearings arepassed inwardly through the openings, and the cheeks are then secured insitu. Such practice is expensive, and furthermore, the removal of a rollfrom, and the insertion thereof into, the side frames is a laboriousoperation and presents the objectionable problem of excessive downtimeof the calender. Too, the fitting of the cheeks in the side framesrequires extreme accuracy and entails great expense. Various other meanshave been employed to permiteasy removal of a calender roll whendesired, but prior to this invention, the normal practices require thestopping of the calender and the calendering process to permitdisconnection of the roll and its accessories prior to removal of theroll from the stack. This has resulted in lost production time or themanufacture of unsaleable material which has had to be reprocessed.

According to known methods of manufacturing paper and paper board, thematerial is conventionally run through the papermaking machine, woundupon rolls, transferred to a calender, uuwound for feeding through thecalender, so` fed therethrough, and again rewound upon other rolls, allwith certain quanta of time lost and material wasted each time the paperor paper board is wound or unwound. Until now, it has not been practicalto run material through a papermaking machine and thence directly into afinishing calender, and all for the 3,244,090? Patented Apr. 5, 1966recognizable reason that'the papermaking machine, once started, can noteasily be stopped for any changing of a damaged calender roll, rolldamage being a never-ending problem in apparatus of the type hereenvisioned. For instance, in operation, pieces of paper or foreignmatter frequently stick to a roll only to be carried around through theopposed nips to cause damage to the surface lof adjacent fiber or paperrolls by producing surface irregularities. Sometimes such material istransferred to second and third rolls and thus damaging further rolls.This effect is also frequently produced by a break in the sheet whilepressure is being exerted upon the rolls so as to induce spots orstreaks in the sheet necessitating the grinding down or otherwisetreating of the surface of the roll so as to4 remove the surfaceirregularities.

As will be readily appreciated, a papermaking machine, once renderedoperational, must run continuously; any interruption in such operationwould result in the pileup or" wasted material while any rollreplacement in the nishing calender is being effected.

Basically, the invention envisioned is illustrated by an embodimentincluding a stationary hardened roll and a pair of movable pressurerolls with cooperant means for moving the movable pressure rolls of thepair into and out of contact with the stationary roll in -seriatim andselectively, as circumstances may dictate.

Furthermore, I have aimed as an object of this invention to provideimproved means whereby to allow calendering directly on the papermakingmachine by offering an ability to replace a damaged or marked roll ofthe unitized calender without machine stoppage, and additionally,without interruption of the passage of the paper web through thecalender.

Another of the objects of this invention is to provided means forquickly applying or relieving the pressure or force urging either orboth lower filled rolls upwardly toward the upper roll with means forindependently controlling the loading on the filled rolls so Ithateither or both rolls may be in open or closed nip positions.

A further object is to provide a mounting for a lower roll which permitsthe same to be quickly shifted away from operative position inconfrontation with the upper hardened roll to permit the free passage ofmaterial between the rolls without damage to either thereof and by meansof which the lower roll can be quickly restored to its operativeposition, all while the rolls are rotating.

As another object, I provide means for moving apart the rolls such adistance as will provide a sufficient access space to allow the makingof repairs in situ, the threading of the material, and the inspecting ofthe equipment so as to determine if removal is indicated.

Also provided is an off-nip drive which constantly rotates the filledrolls in open nip position to prevent burning of the filling andaccelerates the filled roll to substantially the same surface speed asthe steel roll prior to the nip being closed, and after the steel andfilled rolls are in contact this drive will be automatically declutchedor over run.

In the drawing, the figure is a View, in side elevation, a calendercomprising an upper calender roll and a pair of lower calendar rolls andprovided with means embodying the invention whereby one or the other ofthe lower calender rolls may be quickly withdrawn from operatingposition in confrontation with the upper calender roll for repair orreplacement purposes and eventual quick and easy restoration to its saidoperating position, whereby this withdrawing and replacement may beaccomplished without reducing the operating speed of the calender andwithout breaking the web of material passing through the calender.

ln explaining the invention, a calender is `shownas embodying a stack ofthree triangularly-related rolls, an uppermost stationary or fixed rolladapted to cooperate with one or the other of a pair of lowermostadjustable and removable resilient pressure rolls 2t) and 30. It will beunderstood, however, that a calender may include any desired number -ofrolls and the novel features of the invention may pertain to anyplurality thereof.

Referring now to the drawing more in detail, the novel features of theinvention will be described.

The three-roll calender includes an upper stationary or fixed topcalender roll 10, as aforesaid, which roll may be formed of steel(hardened or soft), chill iron or other suitable metal with or without ahardened and ground or polished or even engraved roll face. Said rollmay be cooled or may be heated as by electricity, hot oil, steam or likemeans and may incorporate automatic temperature control devices. Toproll 10 may be mounted upon or unitary with a top roll shaft 12 which ismounted in the usual'oppositely-disposed roller bearings or othersuitable anti-friction means supported in appropriate bearing housing,all as will appear.

The lower rolls and 3G may be filled rolls iilled with a non-metallicmaterial, as for instance cotton, held on steel shafts'22 and 32respectively under endwise pressure induced by end members which arelocked to the respective shafts. The shafts may be bored for heating orcooling purposes.

.The roll shafts extend beyond the opposite ends of the respective rollsand these shafts are rotatably mounted in bearing housings for supportrelative to suitable frames at opposite sides of the calender.

Each frame, preferentially though not obligatorily, will be made ofheavy-welded, stressed-relieved, steel construction and will be ofgenerally triangular configuration formed by a pair ofhorizontally-spaced vertically-disposed uprights 40 upstanding from andsecured to a base plate 42 or foundation as by bolting 44, and generallyangularly-inclined as to each other so as to converge toward each otherat the triangle apex in manner to allow a relatively narrowvertically-disposed operating area therebetween at their upper portionsand further to allow a relatively wide operating area therebetween belowthe said upper portions.

The opposite frames are held in transversely-spaced relation as to eachother as by tie means in the form of tie rods of conventional style,each tie rod being secured to the upright of one frame into itscounterpart upright of the other frame as by suitable bolting 52, allwhereby the said frames are suitably spaced as to each other fordisposition at opposite ends of the rolls which they support.

A top or stationary roll support plate is iixedly mounted on top ofuprights 4t), di? of each frame of the pair thereof as by suitablebolting 62 so as to interconnect the uprights and to depend downwardlythrough the provided relatively narrow operating area therebetween inmanner to extend therethrough and to terminate within the providedrelatively wide operating area therebelow.

Top roll shaft 12 for top or stationary roll 10 is journalled insuitable bearings 14, as for example roller bearings, mounted in theadjacent of the top roll support plates 60 at each end of the roll, eachbearing being held in its respective support plate 60. as by an outerend plate 63 secured to the support plate 60 as by bolts or screws 6.4,all thereby to hold the ends of the shaft against axial movementrelative to support plates 6ft, 60 and to retain a lubricant for thebearing. Cooled, filtered, oil may be circulated therethrough to provideample lubrication and cooling for the bearings.

By such means, the steel or iron calender roll 1t) is fixed in itslocation respective to the frames of the pair and is, in effect,anchored to the sides of the frame.

The opposite eudS Of the tWo lower roll shafts 22 and 32 for the lowerpressure rolls 20 and 30 respectively are each journalled in suitablebearings 24 and 34 respectively, as for example roller bearings,suitably mounted in the adjacent trunnion or bearing housing or block 26and 36 respectively at each end of the respective roll. Each suchbearing is held in its respective bearing housing as by an outer endplate 28 or 38 secured to the respective bearing housing 26 or 36 as bybolts or screws 29 or 39, thereby to hold the ends of the respectiveshaft against axial movement relative to its trunnions or bearinghousings and to retain a lubricant for the bearing. Cooled oil may becirculated therethrough.

In the case of each bearing housing 26 and 36, a removable gib 70 isiixed thereto as by suitable bolting '72 to provide a guideway to seaton an elongated machined way 74 secured to the inwardly-extending faceof the respective upright 4t) of the frame by any suitable means, thebearing housing being slidably adjustable lengthwise of its respectiveWay. The removable gibs allow the easy removal of the rolls from theframes.

Thus it will be seen that the sides of the frame have machined ways onwhich the illed rolls may slide, one roll on each leg of the providedtriangular arrangement.

A limit stop '76, tixedly secured to each way 74 as by bolting 78 servesto limit the withdrawal or downward movement of the respective bearinghousing along its upright and way thereof.

Roll shafts 12, 22 and 32 preferentially are formed of forged steel andmay be bored therethrough for purposes of receiving water or air orother cooling or heating medium therethrough.

One outer extremity of shaft l2 of top roll 1t) may be extended inmanner to accept a drive from a suitable main power means (not shown)such as for example a motor directly connected or gear driven orconnected by a roller chain, V-belt or timing belt to an appropriatesprocket on the shaft and means may be provided to synchronize the rolldrive with any other machine or machines in the line. j

`One outer extremity of each of the shafts 22, 32 of lower rolls 26, 30respectively may be extended in manner to accept a drive from such as anoff-nip, variable speed, drive motor (not shown) functioning to slowlyrotate its respective roll when the nip is open and to accelerate itsrespective roll to operating speed when and as the nip is being closed,it being of course understood that top roll it) and lower rolls 20 and30 are driven in directions to advance the material to be passed throughthe calender from one end thereof to the other.

An over-riding or declutching means may be provided for the o-nip drivemotor to ensure that the top roll drives the filled roll when they arein contact without any hindrance from the off-nip drive motor.

lf desired, the opposite extremity of top roll l0 may be extended forthe accommodation lof slip rings, connecting gears, heating and coolingconnections, and like contrivances.

The bearing housings for the lower filled rolls are motivated upwardlytoward the top roll by any usual or suitable hydraulic or power actuatedmechanisms 80 or cylinder motors, each of which includes a ram or pistonor plunger 82 arranged in the upper bore of a ram cylinder housing 84,which mechanisms are each located in the base of their respectiveupright. Screws S6 hold seal cover plates 87 of the ram cylinderhousing.

Piston caps 88 are suitably mounted upon the outer free ends of the ramsor pistons or plungers 82. CylinderA housing 84 is closed at its upperend by a removable closure member or cap 89. Fluid under pressure maypass in known manner to and from the lower portion of the cylinderhousing through a suitable pipe or duct (not shown) for urging thepiston 82 against and away from the respective bearing housing, indirections par-. allel to the machined ways, whereby to exert forceagainst the respective bearing housing, the opposite pisy.

factors.

tons at the opposite ends of a lower roll acting unisonly to drive therespective bearing housings toward and away from the top roll so as toforce the respective lower roll toward and away from the top roll. Thatis, when pressure is applied, the pistons move parallel to theirrespective ways and exert a loading on the bottom of the filled rollbearing housings to close the nip.

The system is such as to permit independent loading of each hydraulic orpower actuated mechanism or cylinder motor.

Screw jacks may be provided on each mechanism to allow the attainment offine adjustment of nip closing and further to allow for changes in thediameter of the filled roll.

Each piston exerts al yielding pressure against its respective bearinghousing, and cooperantly, the pistons force the lower roll upwardlyagainst the top roll or into contact with a web of sheet material Wwhich is pressed between the rolls.

When fluid under pressure is supplied to the cylinder housings, thepistons thereof will move upwardly, for example into the position shownon the left side in the figure and causing the slidable cylinders andthe hydraulic piston caps to move upwardly a corresponding extent.

Generally, the upward movement required to motivate the lower roll intopressing relationship with the top roll is not very great, one quarterinch upward movement, for example, being generally suiicient f-or suchpurpose. The extent of this movement may vary considerably, however,depending on the size of the calender and other Greater upward movementis desirable in this instance to present a suiiicient amount of spacefor the convenient removal of a filled roll with its bearings andhousings.

A guide roll 90, suitably journalled between the pair oftransversely-spaced uprights at the leading side of the calender servesfor the entrainment of web W therearound before its passage around toproll and a guide roll 92, suitably journalled between the pair oftransverselyspaced uprights at the trailing side of the calender, servesfor the entrainment of web W therearound following passage of the webaround top roll 10.

In the construction shown, it is assumed that the material W to becalendered enters from the left of the figure over guide roll 90 andinto the bight between top roll 10 and lower roll 20.

In vertically-aligned position below each of the lower rolls and 30, apair of spaced transversely-extending roll carriage tracks or rails 110are provided, same being fixedly mounted upon suitable tie members 112stationarily secured to the frames or foundation at opposite sides ofthe apparatus as shown. Alternatively, such tracks or rails could bemachined in the base.

Each pair of tracks or rails supports a wheeled roll carriage, indicatedgenerally by 114, and constituted by a welded steel cradleorroll-supporting chassis 116 mounted on a pair of spaced axles 118,each -of said axles mounting at each of its opposite ends a flangedwheel 120 in known manner.

Additionally, each wheeled roll carriage 114 will incorporate a manuallyoperated hydraulic lift 122 or a pair thereof for effecting the raisingand lowering of the cradle relative to the wheels thereby to effectlifting of a new or repaired roll into position for attachment to theframes, to support -a damaged roll while removing the gibs, and/or tolower a damaged roll to a convenient level for removal from the frames.

A shut-off valve (not shown) may be placed in the hydraulic circuit sothat the cradle height may be maintained at any desired level.

In the operating sequence, the main drive motor is started to rotate toproll 10 at a slow threading speed and the off-nip drives are started forrotating the lower filled rolls. Pressure is then applied to thehydraulic cylinders serving filled roll 20 to effect a closing of the 6nip between top roll 10 and filled roll 20, the off-nip drive of roll 20accelerating the said roll to threading speed as the nip closes. The webof material is then threaded through the calender. Pressure is appliedto the desired loading to the hydraulic power control means of filledroll 20. rIlhe operating speed is then accelerated to normal and themachine is fully operative.

Through operational use, filled roll 20 may .become damaged frommarking, burning, dirt or other causes. When desired to substitute thefilled rolls, pressure is applied to filled roll 30 so as to close thenip between it and top roll 10, all without vany stopping or retardingthe speed of the calender. The off-nip drive of filled roll -30accelerates 4the said roll to operating speed before the nip closes, anover-riding clutch disconnecting the offnip drive motor just beforeclosing of the nip. Hydraulic pressure is increased to the operatinglevel. When filled roll 30 is satisfactorily operational, the pressureon filled roll 20 is released to permit the nip thereof to open and theroll to descend to the limit stops.

The roll carriage is moved into position under filled lroll 20 from theside of the calender opposite the main drive. The operator manuallylactuates the hydraulic lift to raise the cradle to the point where theroll bears thereupon and the weight thereof is supported thereby. Thegibs for -filled roll 20 are removed. IPressure on the hydraulic lift isgradually released until the roll and carriage reach lowered positionsat a height convenient for the removal of the roll from the frames. Allauxiliary piping and wiring are disconnected from filled roll 20, andthe roll and its bearings and housings are then removed through theframe on the side opposite the drive. Meanwhile filled roll 30 continuesto process the material until it is damaged, when a new filled roll 20can be installed.

To install a new or repaired filled roll in the filled roll 20, theabove procedure is reversed. When the replaced filled roll is mounted onthe frames, the off-nip drive motor is started to keep the roll rotatingat slow speed to prevent any excessive heat from burning a local spot onthe filling and to equalize any sag -in the roll due to its own weight.

Thus, when filled roll 30 is ready for replacement, filled roll 20 is inthe frames ready to be moved into position for closing the nip, andfilled roll 30 may be removed in a manner similar to that used forfilled roll 20.

All drives are arranged so the gib bolts are accessible while thecalender is operating, and all connections and disconnections to thefilled rolls can be made without disturbing the web or reducing thespeed of the calender.

Such on-machine calender will be seen to make it possible to exchange orreplace the filled roll of various types of calenders without breakingthe web or reducing the speed of the machine. Utilizing this or similardesigns, it is possible for a paper manufacturer to have a continuousweb of material from the beginning of the papermak-ing machine to theend of the final finishing calender. The possible economies from thistype of operation are large and obvious, no losses from unwind andrewind operations, less handling at intermediate stages, no lostproduction time while changing filled rolls, less equipment required,less personnel, less power required, to mention but a few.

I therefore particularly point out and distinctly claim as my invention:

1. A three-roll calender comprising, a pair of spaced frames, an upperstationary roll and two lower filled rolls provided with roll shaftsextending beyond the ends thereof with the axes of the roll shafts beingdisposed in triangular arrangement, bearings for said roll sh-aftsmounted relative to said frames of said pair thereof and cooperatingwith the end portions of said roll shafts, housings on which saidbearings are supported, ways on said frames of said pair thereof inwhich said housings are releasably and slideably mounted to permit saidlower rolls to move in seriatim and selectively toward and from saidupper roll, means located below and acting on said housingsv of saidlower rolls for urging said lowerv rolls upwardly toward and downwardlyyaway from said upper roll, a roll carriage between said frames locatedbelow and vertically alignable with each said lower roll,- means forselectively raising and lowering said roll carriage Wherefby saidcarriage maybe moved into yand out of supporting engagement with one ofsaid rolls to selectively permit the removal of said roll housings andsaid oney of said rolls from the frames and the engagement of Isaid rollhousings and said one of said rolls with said frames, said frames beingso spaced as to permit the removal of said carriage from its positiontherebetween.

2.. A three-roll calender as set forth in cl-aim 1 including pairs oftracks disposed below and vertically aligned with said lower rolls, saidcarriage being rollable along said tracks.

References Cited by the Examiner WALTER A. SCHEEL, Primary Examiner.

LOUIS O. MAASSEL, Examiner.

1. A THREE-ROLL CALENDER COMPRISING, A PAIR OF SPACED FRAMES, AN UPPERSTATIONARY ROLL AND TWO LOWER FILLED ROLLS PROVIDED WITH ROLL SHAFTSEXTENDING BEYOND THE ENDS THEREOF WITH THE AXES OF THE ROLL SHAFTS BEINGDISPOSED IN TRIANGULAR ARRANGEMENT, BEARINGS FOR SAID ROLL SHAFTS,MOUNTED RELATIVE TO SAID FRAMES OF SAID PAIR THEREOF AND COOPERATINGWITH THE END PORTIONS OF SAID ROLL SHAFTS, HOUSINGS ON WHICH SAIDBEARINGS ARE SUPPORTED, WAYS ON SAID FRAMES OF SAID PAIR THEREOF INWHICH SAID HOUSINGS ARE RELEASABLY AND SLIDEABLY MOUNTED TO PERMIT SAIDLOWER ROLLS TO MOVE IN SERIATIM AND SELECTIVELY TOWARD AND FROM SAIDUPER ROLL, MEANS LOCATED BELOW AND ACTING ON SAID HOUSINGS OF SAID LOWERROLLS FOR URGING SAID LOWER ROLLS UPWARDLY TOWARD AND DOWNWARDLY AWAYFROM SAID UPPER ROLL, A ROLL CARRIAGE BETWEEN SAID FRAMES LOCATED BELOWAND VERTICALLY ALIGNABLE WITH EACH SAID LOWER ROLL, MEANS FORSELECTIVELY RAISING AND LOWERING SAID ROLL CARRIAGE WHEREBY SAIDCARRIAGE MAY BE MOVED INTO AND OUT OF SUPPORTING ENGAGEMENT WITH ONE OFSAID ROLLS TO SELECTIVELY PERMIT THE REMOVAL OF SAID ROLL HOUSINGS ANDSAID ONE OF SAID ROLLS FROM THE FRAMES AND THE ENGAGEMENT OF SAID ROLLHOUSINGS AND SAID ONE OF SAID ROLLS WITH SAID FRAMES, SAID FRAMES BEINGSO SPACED AS TO PERMIT THE REMOVAL OF SAID CARRIAGE FROM ITS POSITIONTHEREBETWEEN.